How can I decide which diagonal to use ?

[paganaye]

With pixi-projection we use square sprite, then inside the application transform it into two triangles.
In my game half the time it looks all right and half the time it looks bad.
How can I fix that.

[paganaye]

I fixed it (badly) using this code.
The question becomes: Is there a better way?

        const rightDiagonal = Math.abs(this.elevations.topRight - this.elevations.bottomLeft)
            <= Math.abs(this.elevations.topLeft - this.elevations.bottomRight);
        if (!rightDiagonal) {
            let tempX = vertexData2d[0];
            let tempY = vertexData2d[1];
            let tempZ = vertexData2d[2];
            vertexData2d[0] = vertexData2d[3];
            vertexData2d[1] = vertexData2d[4];
            vertexData2d[2] = vertexData2d[5];
            vertexData2d[3] = vertexData2d[6];
            vertexData2d[4] = vertexData2d[7];
            vertexData2d[5] = vertexData2d[8];
            vertexData2d[6] = vertexData2d[9];
            vertexData2d[7] = vertexData2d[10];
            vertexData2d[8] = vertexData2d[11];
            vertexData2d[9] = tempX;
            vertexData2d[10] = tempY;
            vertexData2d[11] = tempZ;
            this.rotation = - Math.PI / 2;
        } else {
            this.rotation = 0;
        }

[ivanpopelyshev]

The question is a bit wrong, we have to make actual quads, not triangles :) The whole point of Sprite2d is how to make weights ([2], [5], [8], [11]) so it actually becomes a projective quad and not two triangles.

[paganaye]

You're telling me I am a sprite abuser.
Well you might be right, but I do with what I have.
Perhaps I need a triangle primitive.
This would allow me to have a different tint for each triangle.

[ivanpopelyshev]

hm, interesting. Yeah, we might need mesh like this. Seriously, that's a mesh problem, mesh with 3 coords per vertex.